An Overview of the Pineal Gland

Posted on- May 03, 2015

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The pineal gland- tiny structure but considered a mystifying organ because it was discovered last of the endocrine glands. It is often called as the “third eye,” primarily because of its location deep in the center of the brain and connection to light. French philosopher Descartes regarded pineal gland as “the seat of the human soul,” the place where all the thought process goes on. His comments were later on rejected.

Even today, researchers are unaware of the full functionality of the pineal gland. Only responsibility the medical world knows of this gland is to produce and release the hormone- melatonin. This hormone is known to regulate reproductive hormones and maintain circadian rhythm. The Pineal Gland Hormone- Melatonin
Situated next to the center of the brain, pineal gland is mainly composed of pineal and neuroglial cells (they play a supportive role to the pineal cells).

The pineal gland releases melatonin hormone. It is a special hormone dictated by light. The hormone has two main functions- to regulate certain reproductive hormones and to control circadian rhythm.

Circadian Rhythm
Circadian rhythm is a 24-hour physiological process represented by sleep-wake patterns. The rhythm totally depends on daylight and darkness. A little exposure to the light stops the release of melatonin which ultimately controls circadian rhythms. Melatonin secretion is high in the night and low in the afternoon, which influences your reaction to the length of day or night. Naturally, this reaction affects sleep patterns but melatonin’s effect on sleep is still under debate.

Reproduction
Melatonin blocks the release of follicle stimulating hormone and luteinizing hormone from the anterior pituitary gland. These hormones are responsible for appropriate functioning of the testes and ovaries.

Diseases associated with the pineal gland
Excess production of melatonin is linked with seasonal affective disorder (SAD) and deficient production of melatonin is linked with insomnia. Other diseases caused by melatonin imbalance include: